Struct FieldLengthError 

pub struct FieldLengthError {
    pub field: &'static str,
    pub len: usize,
    pub min: usize,
    pub max: usize,
    pub unit: LengthUnit,
    pub constant: &'static str,
    pub fix: &'static str,
}

A field of a write is empty or longer than its limit. The message is meant for agents in full: field, size, the limit and its unit, its constant and what to do (the Steward, 2026-10-15). One type for every write path’s length check (0.91.4: with a unit and a minimum, so the fields counted in characters use it too)

Fields

field: &'static str

len: usize

The value’s length, in unit

min: usize

0 when the field may be empty

max: usize

unit: LengthUnit

constant: &'static str

fix: &'static str

Implementations

impl FieldLengthError

pub fn check( field: &'static str, text: &str, (min, max, unit): (usize, usize, LengthUnit), constant: &'static str, fix: &'static str, ) -> Result<(), Self>

Ok when text is min..=max long in unit. Text that is only whitespace counts as empty when min is above 0.

Trait Implementations

impl Clone for FieldLengthError

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FieldLengthError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for FieldLengthError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for FieldLengthError

impl Error for FieldLengthError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<FieldLengthError> for AgentNameError

fn from(source: FieldLengthError) -> Self

Converts to this type from the input type.

impl PartialEq for FieldLengthError

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for FieldLengthError